disc

RCA CED VideoDisc interactive (1983 – 1986)

In 1983, RCA launched a version of their CED VideoDisc system that offered random access to enable interactive features for educational and entertainment titles. The discs were ‘banded’ to allow the user to skip to a different segment.

Two models of VideoDisc player offered the ability to play the interactive disks – the SJT400 and the SKT400 – and these could be used with their own 30-button remote control, or RCA’s Digital Command Centre which could also operate certain RCA televisions and VCRs.

Just a handful of VideoDiscs were produced that made use of the interactive features, including initially ‘A Week at the Races’ (with races arranged so that participants didn’t know which horse would win) and ‘Many Roads to Murder’ (with 16 different murder mystery scenarios). The interactive titles were housed in black caddies to distinguish them.

RCA ceased production of CED VideoDisc players in April 1984. Although CED VideoDiscs continued to be sold into 1986, there were only ever a handful of interactive titles produced and these are now rare.

A couple of titles, NFL Football CED-1 (San Diego Chargers vs. Oakland Raiders) and NFL Football CED-2 (Dallas Cowboys vs. Washington Redskins), were designed for use in the Bally Midway NFL Football arcade console. This console offered live action footage via the CED VideoDisc played in an RCA SJT400 player inside the machine.

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Blu-ray/DVD combo disc (2009 – early 2010s)

In the early days of the Blu-ray Disc, a few discs were released that offered the full movie in both DVD-Video and Blu-ray formats on the same disc. The disc essentially consists of a Blu-ray Disc and a DVD disc glued together to create a double-sided disc, packaged in a standard Blu-ray Disc case. These discs, sometimes called ‘flipper’ discs, had very small centre labels and were prone to fingerprints.

Universal Studio seems to have been the first to release a Blu-ray/DVD combo disc, with the Bourne Trilogy films. It meant, for instance, that people could watch the Blu-ray version at home, and the DVD on a portable DVD player or at a friend’s house that didn’t have a Blu-ray player.

The idea wasn’t entirely new, with the HD DVD/DVD Combo Format disc doing the same thing in 2006, to try and boost sales.

The idea doesn’t seem to have become widespread, and combo packs with both versions on separate discs became more popular.

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Dynaquad (1970 – 1976)

In 1969, Dynaco introduced a system to ‘derive’ surround sound from stereophonic LPs by using a passive electronic circuit called a Hafler Circuit. This was designed by Dave Hafler of Dynaco in the early 1960s and required four speakers in a diamond configuration for derived quadraphonic (2:2:4) sound.

Around 1970, Dynaco introduced the Dynaquad system for encoding matrixed quadraphonic sound (4:2:4). The system was similar to EV Stereo-4 (EV-4) introduced in 1970, and was broadly compatible.

A sampler disc for the Dynaquad system was released in 1971 on the Vanguard Records label, and by this time it was suggested that the four speakers were placed in the four corners of the room rather than the diamond configuration.

Very few records appear to have used Dynaquad encoding. The 1970 eponymous album by The Flame may have used Dynaquad, along with some of the ‘Environments’ series by Syntonic Research. There were also some LPs and 7-inch singles produced by KL Recordings in the mid-1970s.

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Harmony Disc Record (1907 – 1916)

Harmony Disc Records was a Chicago-based record label launched by the Great Northern Manufacturing Co. in 1907. It produced 10-inch shellac records that were identical to other disc records of the time, except for a large centre hole of ¾-inch diameter. The larger hole was so that only Harmony Disc Records could be played on the Harmony Talking Machine.

Harmony was one of a number of Chicago-based labels that operated a premium scheme whereby the phonograph itself was inexpensive but the purchaser was locked-in to purchasing discs made for the player since the player had a correspondingly larger center spindle to prevent discs with standard holes fitting onto the turntable.

Harmony Disc Records were sometimes single-sided in the early days, and all were 10-inch in diameter.

Around 1912, Great Northern Manufacturing Co. left the record business, and Columbia took over the Harmony Disc Record label, which was renamed Harmony Record with the company name as Harmony Talking Machine Co. Columbia resurrected the Harmony name in 1925, but this time with a standard centre hole.

As well as the Harmony Disc Record, the other Chicago-based labels included Standard Disc Record (½-inch centre hole), United Records (1½-inch centre hole), Aretino Records (3-inch centre hole), and Busy Bee Records (rectangular cut-out in addition to standard ¼-inch centre hole).

In 1916, Harmony, Standard, United and Aretino were brought together under the Consolidated Talking Machine Company. It’s unclear when the Harmony Record label was discontinued and it may be that like the Standard Disc Record label, some recordings would have been available for a while with the larger centre hole.

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HMV Nursery Records (1923 – 1930)

This was a short-lived series of double-sided 7-inch 78rpm records aimed at children. Their catalogue numbers all begin with AS and their labels were orange.

There were 43 records in the series, all of which were issued between 1923 and 1925 except for AS 43 which was issued in 1930.

In a 1930 catalogue of records for schools, the AS series records are priced at 1/6 (one shilling and sixpence in old UK currency, or 8 pence in decimal currency).

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ISI 525 WC Optical Storage System (1985 – late 1980s)

Around 1985, ISI (Information Storage Inc.) introduced their 525 WC Optical Storage System. This was one of a number of magneto-optical disc storage formats introduced in the mid-1980s, and allowed users to record data to an optical disc in the days before CD-R and CD-RW.

The 525 WC used the 5.25-inch disc format, allowing the drive to be installed internally in a PC with a full-height 5.25-inch floppy disk drive bay, or alternatively it could be purchased as an external drive.

Single-sided and double-sided discs were available, with a capacity of 115 or 230 MB respectively. The discs were pre-formatted, and were WORM (write-one, read many) capable.

In 1988, ISI introduced the 525-GB, an incompatible system that offered 600 MB per disc side (for 1.2 GB capacity on a double-sided disc).

Figures

Dimensions: 150 mm × 137.5 mm × 10.5 mm

Capacity: 115 MB to 230 MB

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Durium Junior (1932 – 1933)

Durium Junior was a flexible single-sided 4-inch phonograph disc made from Durium (a synthetic brown resin invented in the US in 1929) with a cardboard backing. These were introduced in 1931 by the Durium Products Corp. who also made the 10-inch Hit Of The Week phonograph records in the US.

The Durium Junior mostly offered advertising and music combined though some were just music, and they played for around one and a half minutes. The format was also used for some childrens records.

The last Hit Of The Week release was in June 1932 and Durium Records in the UK ended production in January 1933. It’s unclear when Durium Junior ended, but it was likely around the same time.

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Aretino Record (1907 – 1914)

Aretino Records were 10-inch (or sometimes 12-inch) 78 rpm shellac records with an unusually large centre hole of three-inch diameter. This was the largest spindle-hole of any record and meant the centre label was reduced to a narrow ring.

The label was based in Chicago in the US, and began producing disc records and the phonograph machines to play them around 1907. The large spindle on the phonograph meant that only Aretino Records could be played on them (though adapters were available to play Aretino Records on other phonograph machines). The players were sold very cheaply since consumers were locked into purchasing Aretino Records to play on them. This was a tactic employed by a number of Chicago-based record labels, including the Standard Disc Record (½-inch centre hole), Harmony Disc Record (¾-inch centre hole) United Records (1½-inch centre hole), and Busy Bee Records (rectangular cut-out in addition to standard ¼-inch centre hole).

Aretino records were produced as single-sided and double-sided 10-inch discs, and as double-sided 12-inch discs.

Aretino was merged with Busy Bee records in 1910, and Aretino records ceased production around 1914.

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SNK Neo Geo CD / CDZ (1994 – 1999)

The Neo Geo CD was released in 1994 and was the second home video game console released by SNK after the Neo Geo AES. The hardware for the Neo Geo CD was very similar as that of both the AES and the arcade version (the Neo Geo MVS) and this meant that games for the AES could easily be adapted.

Using a CD-ROM for distributing games rather than the large ROM cartridge of the AES meant that they could be produced and sold at much more affordable prices.

The first version (sold only in Japan) used a tray-loading drive, whereas the version eventually marketed worldwide was top-loading. Both of these versions used single-speed drives, which meant very long load times on larger games. The later CDZ version released at the end of 1995 (only sold in Japan and also top-loading) offered faster load times, but it’s unclear if this was due the use of a double-speed drive or simply a larger CD cache.

All versions of the Neo Geo CD could play audio Compact Discs.

Most of the titles released for the Neo Geo CD were ports of titles available on the AES. A few MVS titles not available on AES were made available for the CD, and there were a few exclusive titles for the CD. In all, there were about 97 officially released games for the Neo Geo CD.

By 1995 the Neo Geo CD was not keeping up with other systems, for example in not offering 3D graphics. It was quietly discontinued in 1997 but like the AES, SNK continued to support it with game releases for a few years longer, with the last official title released in 1999.

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Mini DVD-RAM (2000 – late 2000s)

DVD-RAM (DVD Random Access Memory) was an optical disk format used in computers, set-top box video recorders and camcorders, and was first introduced in 1998.

DVD-RAM was more commonly available as a 120 mm (5-inch) disc with or without a protective caddy, but smaller 80 mm (3-inch) mini DVD-RAM discs introduced in 2000 were available specifically for camcorders, with a capacity of 1.46 GB for a single-sided disc, and 2.8 GB for a double-sided disc. These could also come with or without a caddy, and there were two different types of caddy available – one was squared off and looked like a smaller version of the 120 mm caddy complete with protective shutter, while the other was much more rounded and had no shutter.

Like the equivalent mini DVD-RW and later mini DVD+RW discs, it was rewritable and used phase change recording, but its data structure was more like a hard disk and the disc could be rewritten without needing to add new sessions. The surface of the disc displays small rectangles that constitute the hard-sectoring of the disc.

The first camcorder to use 80 mm mini DVD-RAM discs was the Hitachi DZ-MV100 in 2000. This used the square style of caddy. At the time, DVD-RAM discs could not be read by most DVD-Video players, and very few computers. Just a handful of camcorders were released in the early 2000s that were capable of recording to DVD-RAM.

The website of the RAM Promotion Group ceased was taken down sometime around 2008, but Panasonic continued to produce DVD-RAM discs until 2019.

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